Improved machine for grinding files



LHqSPENGER. MACHINE FOR GRINDING FILES.

Patented July 25, 1865.

'ment.

UNITED STATES PATENT OFFICE.

ISAAC HJSPENOER, O F PAWTUOKET, RHODE ISLAIlD, ASSIGNOR TO 'H[M- SELF AND ANDREW R. SLADE, OF SAME PLACE.

-IMPROVED MACHINE FOR GRINDING FIILES.

Specification forming part of Letters Patent No. 49,042 dated Jul 25 1865.

To all whom it may concern:

Be it known that I, ISAAC H. SPENCER, of Pawtucket, in the county of Providence and State of Rhode Island, have invented a new and Improved Machine for Grinding Files; and

I do herebydeclare that the following me full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 represents a sectional side elevation of this invention. Fig. 2 is an end view ot'thc same, partly in section. Fig. 3 is a plan or top view of the same.

' Similar letters of reference indicate. like parts.

The object of this invention is to grind fileb'lanks by machinery instead of by hand-labor, the usual method of grinding files being to hold them up against a grinding-stone until their surfaces become perfectly smooth and fit for cutting.' This method not only requires much time and constant attention, but it is also very'difficult, or, in fact, impossible to produce files of a perfectly unitorm shape.

In the machine which forms the subject-matter' of this present invention the. files are secured, one after the other, on a carriage which 1 moves under a revolving cutter or grindingwheel on a curved bed in such a manner that the shape of each file depends entirely upon the curvature of the bed, and as long as this form in shape, and the operation of grinding can. be conducted by a person of little mechanical knowledge or experience, and with little personal attention. The files, on being placed on the carriage, are held in position by a sliding clamp, which is operated by a toothed seg- This segment connects with a hand lever-by means of a strap and hinged dog in such a manner thatwhen the clamp has been .made to catch over the end of the file the hinged dog will lock the toothed segment and prevent the clamp from releasing the file spontaneously.

gear, which is composed of a large cog-wheel,

a, keyed firmly to the rear end of the spindle,

and'gearing in a pinion,.b, the axle of which has its bearings in an-adjustable hand-lever, c. This lever has its fulcrum on a. pivot, d, secured in'the end of the bed A, and by raising the handle of the same/the pinion b is depressed and thrown out of gear with the cog-wheel a. ()n the same axle which bears the pinion b is also mounted the cog-wheel e, which gears in a. pinion, f, mounted oathehorizontalshaftg, and by the action of the pinionj; cog-wheel'c, pinion b, and cog-wheel ct, the motion of the shaft 9 is transmitted to the screw-spindles C. By using the handle of thehand-lever the cogwheel 0 is disengaged from the pinion f,- and at the same time the pinion b is thrown out of gear with the cog-wheel a, and the connection between the shaft 9 and screw-spindle C is broker or interrupted. The connection between the shat't g and spindle G can, however, be efiected also by a cog-wheel, h, which is mounted on the shaft 9, and which gears in a siinilarwl1eel,t',thatturnslooselyonithespindle.

A sliding clu-tch,j, serves to render the cogwheel 6 rigid with the screw-spindle, and in this case the motion of the shaft 9 is transmitted to the spindle U by the action of the cog-wheels h t. It must be remarked, however, that whenever the wheel '6 is rendered rigid with. the screw-spindle the pinions b and cogwheel 6 must be depressed or thrown out of gear with the pinion f andoog-wheel a, since the action ofone set of wheels would interfere with that of the other set. The proportion of the wheels and pinions a b e f is such that by their action the screw-spindle receives a slow rotary motion with the direction of the This carriage is moved back and arrow marked near it -in Fi g. 2, and the requiwith a socket in its end, which catches over. I the point of the tail of the file. It is furnishedwith. cogs 'lon its upper surface, which 'gear in a toothed segment, m. This toothed seg- Inent swings freely on the pivot a, which also forms the fulcrum for the hand-lever H,.and it is operated by a hinged dog, 1), which connects with an arm extending from the hand-lever [by means of a strap, 9, as clearly shown in Fig. 1 of the drawings.

1f the'hand-lever is thrown back in thedirection of the arrow marked near it in Fig. 1, the dog 1) locks the same andholdsit in such a position that the, clamp is notallowed to release the file spontaneously. By turning the hand-lever in thedirection opposite said arrow the sliding clamp is drawn back andth'e file is released.

y The surfa'ceof the file is ground off by a cutter, I, audits edge by a cutter, J The cutter I is mounted on a shaft, K, which has-its bearings in adjustable boxes, so that the teeth of the cutter can be made "to bear with more or less forceon the surfaceof the'file. Motio'uis ,itnparted'to said shaft by suitable gear-wheels f f m the driving-shaft L, and its speed is adjusted. to correspond to the nature of the files and to the cutter.

The cutter J is mounted on a vertical spindle, M, which has its bearin gs in suitable boxes on the side of the bed, and to which motion is imparted by suitable gear-wheels from the driving-shaft. This cutter is intended to act on the edge of the file, as previously stated, and

.- in order to keep the file up to the cutter-an adjustable strip, N, is fastened to the top of the carriage, and set-screws 1' Serve to force the same up against the file and bring the file in the proper position in relation to the cutter.

By the combined action .of the twocutters I J the surface and the edge of thefile are ground oif simultaneously, and after one side and edge have been finished the file is turned round and the other side and edge are ground oft' inthesame manner. The edges of the file are thus rendered perfectly parallel, and by thecurved bed both surfaces are turned out of a'uniform shape. A large number of files.

can thus be ground-perfectly alike and of a uniform shape, and the operation of grinding requires littletime and no skill.

' Having thus described inyinvention, I claim as new and desire to secure by Letters Patent 1. The within-described method of grinding files by placing them on a carriage moving on acurved bed and exposing them to the action of one or more cutters, substantially in the .manner and forthepurpose herein set forth.

2. The sliding clamp F, in combination with the toothed segment m, hand lever H, and

hinged dog 12, constructed and operating substantially as and'for the purpose described.

3. The combination of the cutters I J with the carriage Band curved bed A, constructed and operating as and for the purpose specified.

' I ISAAOH. SPENCER. Witnesses:

JOSIAH Wnrrn, CHARLES FLANDERs. 

